Computer and network systems such as personal computers, workstations, server systems, and cloud storage systems, typically include data storage systems for storing and retrieving data. These data storage systems can include data storage devices, such as hard disk drives, solid state storage devices, tape storage devices, and other mass storage devices.
In examples of magnetic storage media, such as rotating media hard disk drives, one or more write heads are employed to write data to the magnetic media, while associated read heads are employed to read data from the magnetic media. These write and read heads are configured during manufacturing to have manufacturer-specified areal read/write densities across the magnetic media, typically measured in bits per square inch, a combination of bits per inch (BPI) and tracks per inch (TPI). These manufacturer-specified areal densities are typically selected based on error rates for the read/write heads as determined during the manufacturing process. However, when particular read or write head elements of a storage device become degraded during operational use, the entire storage device is typically replaced.
To achieve a measure of reliability and availability, data storage systems can include multiple data storage devices in various arrays and configurations. One such data storage system is a redundant array of independent disks (RAID) and can be configured in with different architectures to satisfy various capacity, reliability, and availability requirements. The degraded performance discussed above can be especially cumbersome for arrayed storage systems. In typical arrayed storage systems, when a single data storage device fails or shows signs of degradation, the failing data storage device is typically discarded and a replacement data storage device is prepared to participate in the arrayed storage system.
Overview
To provide enhanced operation of storage media associated with data storage devices, such as rotating media-based hard drives, various systems, methods, and firmware are provided herein. In some examples, these systems, methods, and firmware can provide for data storage devices that include magnetic storage media configured to store data, read heads configured to read data from the magnetic storage media at associated areal densities, and a storage processor. The storage processor is configured to monitor read error rates of the read heads during operation of the data storage device to identify a degraded one of the read heads, and process at least the read error rates and an areal density of the degraded one of the read heads to modify the areal density of at least the degraded one of the read heads.